Process for rendering polysaccharidic materials water resistant



Patented Dec. 23, 1941 PROCESS FOR RENDERING POLYSACCHA- RIDIC MATERIALS WATER RESISTANT Alva L. Honk, Philadelphia, and W. H. Bock.

Glenside, Pa., assignors to pany, Philadelphia, Pa.

No Drawing. Application December 15, 1939, Serial No. 309,398

14 Claims. (c1. 91-73) This invention relates to a process for increasing the water-resistance of polysaccharides. It deals with a reaction of polysaccharides, and

' any of their derivatives which contain available hydroxy groups, with an acid salt of .an aldehyde having attached to the a-carbon atom a substituted aminomethyl group which is free from aromatic groups. More particularly it concerns making cellulosic fibers lessaffected by water and the insolubilizing of water-soluble hydroxyl-containing sizing materials whether in pellicles or coatings.

It is generally recognized that most polysaccharides are sensitive to water. Some polysaccharide products are water-soluble while others,

although not soluble, become highly plastic when wet, change in form, lose strength, etc. The polysaccharides which are used as sizing materials must be soluble in water to allow their direct application to fabrics, but ready water-solubility also prevents their retention when the fabric is wet or laundered. Films or pellicles formed from aqueous dispersions or solutions have likewise suffered from the ease with which such films can be redissolved.

It is an object of this invention to provide a practical method for increasing the water-resistance of polysaccharides and their ether and ester derivatives having free hydroxyl groups. It is an object to render insoluble such sizing materials as starch, hydrolyzed starch, converted starch and water-soluble cellulosic derivatives. It-jszanother object to stiflen fabrics permanently. It is also an objectto stabilize cellulosic fabric byincreasing the water-resistance of the fibers composing the fabric. It is a further object to insolubilize films on'a cellulosic fabric base and at the same time stabilize the base. It

through a hydroxyl group. Starches, dextrine,

ethyl starch, methyl cellulose, ethyl cellulose,

hydroxy-ethyl. cellulose, partially esterified cellulose and similar water-soluble sizing materials are rendered insoluble and. wash-fast. Pellicles & Haas Comof .such materials are rendered water-resistant. Cellulose, in such forms as cotton or linen, regenerated cellulose, cellulose ethers and esters, and other non-waterasoluble polysaccharides and their hydroxyl-bearing derivatives become lessafiected by water. Fabric made from such materials becomes more stable, as, for example, against shrinkage. Cellulosic fabric carrying sizing may be treated with an acid salt of an aldehyde having attached to the a-carbon atom a substituted aminomethyl group free from aromatic groups to render the sizing insoluble and highly adherent to the fabric base.

The term water-soluble polysaccharide or hydroiwl-bearing derivative" has been used to designate those polysaccharidic materials which are dispersible in water with the formation of true or colloidal solutions. Q

The acid salts of the aminoaldehydes which are preferred in this process possess the general formula heating together an acid salt of a strongly basic. non-aromatic amine having at least one hydrogen onthe-amine nitrogen, formaldehyde, and

an aldehyde having a hydrogen atom on the a-carbon atom. An alternate method of preparation is the addition of an amine to an unsaturated aldehyde followed by conversion to an acid salt. The first-mentioned method of preparing these condensates has already been described (Ber. 65B, 3'78 (1932)). Suitable aldehydes include propionaldehyde, isobutyraldehyde, valeraldehyde, crotonaldehyde, 2-ethylhexaldehyde, heptaldehyde, hexahydrobenzaldehyde, etc. The preferred aldehydes have not more than eight carbon atoms. The amines which may be used are non-aromatic primary and secondary amines, typical of .which are methylamine, dimethylamine, ethylamine, dibutylamine, methylpropylamine, methylbenzylamine, cyclohexylamine,

diallylamine, ethanolamine, diethanolamine, etc. It is best to use amines which contain aliphatic groups of less than eight carbon atoms. The smaller groups are economically advantageous as the amine grouping is split out in the reaction with a polysaccharide. Any acid may be used to form a salt with the amine, hydrochloric, formic, acetic, and lactic acids being particularly useful examples.

The following procedures will illustrate the preparation of aminoaldehyde condensates.

Pasrm'rrox A A'solution containing 11 parts of acetaldehyde, 75 parts of 30% formaldehyde, and 61 parts of di- 2,267,277.. morphollne, piperazine, piperidine, allylamine,

' hyde salt are preferably dried together and then methylamine hydrochloride in 100 parts of water i was stirred one hour at room temperature. Some heat was evolved. The solution was stirred two hours more, during which period it was gradually heated to 70 C. After mixture had stood for two days, it was concentrated in vacuum to a white paste. The yield was 91parts. The material thus obtained had a nitrogen content of 10.38%, the theoretical value being 10.2%.

PREPARATION B A mixture of 326 parts of dimethylamine hydrochloride, 120 parts of paraformaldehyde, 100 parts of ethanol, and 290 parts of isobutyraldehyde was stirred at 70 C. for five hours. Crystals formed around the sides of the flask. The mixture was cooled, filtered, and the solid washed with acetone. The yield was 265 parts.

PREPARATION C A mixture of 17 parts of redistilled heptaldehyde, 24.5 parts of dimethylamine hydrochloride,

9 parts of paraformaldehyde, and 100 parts of methanol was stirred three hours at 75-80 C., concentrated to a soft solid, and dried further in a desiccator. The yield was 3'? parts.

PREPARATION D Fifty parts of anhydrous dimethylamine was distilled into 70 parts of a-methyl acroiein. The mixture was allowed to stand 15 hours at 05 C. and then warmed up to room temperature for 6 hours. It was then distilled. The yield was 85 parts of sl-dimethylamine isobutyraldehyde, having a boiling point of 40-56 C. at 28 mm. pressure. Any desired salt of this amine can be obtained on neutralization with an acid.

The salts of aldehydes having a non-aromatically substituted aminomethyl group attached to the m-carbon atom (which may also be termed ,B-substituted aminopropionaldehydes) are water-soluble and are preferably applied in solution form. A fabric or sized fabric which is to be treated may be dipped, sprayed or coated with a solution. One of the condensation products may also be incorporated in a sizing bath by addition thereto or the condensate may be mixed with size to yield a composition ready for use. A condensation product may also be added to solutions droxyethyl cellulose and 1 part of a-dimethyh' from which pellicles are to be formed, or films of polysaccharidic material may be first formed and then treated with a solution of a condensate. With the polysaccharidic material and aminoaldehyde there may be used fillers or pigments, such as clay, talc, titanium dioxide, etc., dyes, plasticizers, softeners, and other modifying agents.

heated between about C. and about 145 C., the allowable upper temperature'being determined by the sensitivity of the treated polysaccharide to heat. The time-required for heating will depend upon the particular materials selected, the temperature, and the degree of waterresistance desired, heating for a few minutes up to an hour usually accomplishing the desired object.

Typical applications are shown in the following examples.

' Example 1 Cotton sheeting was dipped through a mixture of 5 parts of an aqueous solution containing 7.5% of hydroxyethyl cellulose and 1 part of a 25% aqueous solution of dimethylaminomethyl acetaldehyde hydrochloride. The cloth was squeezed, dried, heated one-half hour at l30-135 C., and washed with a hot soap solution. A very stiff, permanent finish resulted.

Example 2 Cotton lawn was coated with a sizing consisting of 60 parts of a 10% tapioca starch paste and 1 part of a-dimethylaminomethyl isobutyraldehyde hydrochloride. -It was dried and treated as in Example 1. A very stiff fabric was obtained.

) Further washing softened it only slightly.

Example 3 A viscose rayon fabric was coated with an aqueous paste containing 6.5% of potato starch and 1.5% of a-dimethylaminomethyl isobutyraldehyde hydrochloride. The cloth was dried and pressed with a medium hot iron for one minute. A firm, stiff finish resulted, which was not removed by laundering. v

Example 4 Cellulose acetate fabric was coated with a mixture of 5 parts of a 7% aqueous solution of hyaminomethyl heptaldehyde hydrochloride. This fabric was then {treated as in Example 1, and a permanently stiffened fabric was obtained.

Example 5' Cotton lawn was coated with a sizing consisting of 20 parts of a 10% tapioca starch paste which had been hailed one hour and 1 part of a-dimethylaminomethyl-2-ethy1hexaldehyde. It was dried and treated as in Example 1. A very stiff, wash-fast finish was acquired.

I Example 6 Cotton thread was impregnated with a solution made by dissolving 1 part of a-monomethylaminomethyl isobutyraldehyde hydrochloride in 20 parts of a 7.5% aqueoushydroxyethyl cellulose solution. The treated thread was dried and heated in an oven at C. The thread became firmer and somewhat stiffened, and this effect was retained throughsubsequent washings.

Example 7 A linen fabric was coated with a starch paste comprising 9.5% of tapioca starch, boiled one hour, and 4.75% of a-dimethylaminomethyl crotonaldehyde hydrochloride. After it had been treated as in Example 1, it became very stiff and light tan in color. Neither effect was removed by washing.

Example 8 Exampl 7 was repeated, using a-morpholinomethyl isobutyraldehyde hydrochloride instead of the crotonaldehyde derivative. A good permanent stiffness was produced.

Example 9 Q Example 1 v A paste consisting of 60 parts of a 10% boiled I starch paste and 1 part of c-dimethylaminomethyl isobutyraldehydehydrochloride was diluted with an equal part of water and spread on a glass plate to form a film. It was dried and heated one-half hour at 130 C. The resultant brittle film was neither dissolved nor softened when boiled in water.

Example 11 A piece of cotton sheeting, 7 x- 10 inches, was held in a frame under tension, and impregnated with a 15% solution of a-dimethylaminomethyl isobutyraldehyde hydrochloride. The treated fabric was put in an oven for 20 minutes at 130- 135 0., removed from the frame, and washed in soap and water at 80 C. After this treatment, shrinkag was determined. It was found that the cloth had gained inch in width and lost inch in length. Untreated cloth under the same conditions gained inch in width and lost inch in length.

Example 12 A mixture of 50 parts of a paste containing 10% tapioca starch which had been boiled one hour, 15 parts of tale, 2 parts of a-dimethylaminomethyl isobutyraldehyde hydrochloride, and parts of water was applied to an 80 x 80 cotton sheeting. The sized fabric was run through a roller to remove excess material, dried, baked one-half-hour at 130 C., and washed. The finished cloth was moderately stiffened and contained about 5% ash.

Example 13 A viscose rayon fabric was coated with a solution consisting of 60 parts of a 8% boiled potato starch paste, 1 part of dimethylaminomethyl isobutyraldehyde hydrochloride, 2 parts of dimethyl benzyl octadecyl ammoniumchloride and sufilcient water to make 120- parts in all. The sized fabric was dried and treated as in Example 12. The fabric was slightly stifiened and had a full hand.

By the process herein described polysaccharides and their hydroxyl-bearing derivatives may be rendered highly water-resistant as the result of their reaction with an acid salt of an a-aminomethyl aldehyde. While this process is generally useful for the improvement of cellulosic-fabrics and films, it is also highly useful in connectio with the sizing of fabrics. imparting a perma-' nent stiffening which is fast to washing and which does not dust out on mechanical working.

We claim: 1. A method for increasing the water-resistance of polysaccharides and their ether and cater derivatives having free hydroxyl groups which comprises treating said material with an acid salt of analdehyde having attached to the a-carbon atom an aminomethyl group having at least one N-substituent selected from the class consisting of aliphatic groups, cycloaliphatic groups,-

aralkyl groups, and saturated divalent aliphatic groups which jointly with the nitrogen form a heterocycle, and heating the treated material.

2. A method for insolubilizing awater-soluble, polysaccharidic sizing'inaterial having free hydroxyl groups which comprises treating the material with an acid salt of an aldehyde having attached to the a-carbon atom an aminomethyl group having at least one N-substituent selected from the class consisting of aliphatic groups,

cycloaliphatic groups, aralkyl groups, and saturated divalent aliphatic groups which jointly with the nitrogen form a heterocycle, and heating the treated material. 1

3. A method for rendering starch sizing .on a

fabric wash-fast which comprisesapplying to the fabric said sizing and an acid salt of an aidehyde having attached to the a-carbon atom an' aminomethyl group having at least one N-substituent selected from the class consisting of aliphatic groups, cycloaliphatic groups, aralkyl groups, and saturated divalent aliphatic groups which jointly with the nitrogen form a heterocycle, and heating th sized fabric.

4. A method for insolubilizing a polysaccharidic sizing on a textfle fabric which comprises applying to the fabric said sizing and an acid salt of an aldehyde having attached to the a-carbon atom an aminomethyl group having at least one N-substituent selected from the class consisting of aliphatic groups, cycloaliphatic groups, aralkyl groups, and saturated divalent aliphatic groups which jointly with the nitrogen form a heterocycle, and heating the sized fabric.

5. A method for increasing the water-resist ance of polysaccharides and their ether and ester derivatives having free hydroxyl groups which comprises treating'said material with an acid salt of a-dimethylaminomethyl isobutyraldehyde.

6. A method for insolubilizing films of poly-,

'- saccharides and their ether and ester derivatives having free hydroxyl groups which comprises treating said polysaccharidic materials with an acid salt of an aldehyde having attached to the a-carbon atom an aminomethyl group having at least one N-substituent selected from the class consisting of aliphatic groups, cycloaliphatic groups, aralkyl groups, and saturated divalent aliphatic groups which jointly with the nitrogen form a heterocycle, forming a film from said treated material, and heating the film.

7. A water-resistant reaction product of a poly group having at least one N-substituent selected from the classconsisting oi! aliphatic groups, cycloaliphatic groups, aralkyl groups, and saturated divalent aliphatic groups which jointly with the nitrogen form a heterocycle. v

9. A water-resistant reaction product .of an hydroxyl-bearingpolysaccharidic material and an aldehyde, having attached to the a-carbon atom an aminometh'yl group having at least one N-substituent selected from the class consisting of aliphatic groups, cycloaliphatic groups, aralkyl groups, and saturated divalent aliphatic groups which jointly with the nitrogen form a heterocycle.

10. Textile material carrying a deposit of an hydroxyl-bearing polysaccharidiematerial, both an aldehyde having attached to the a-carbon,

atom an aminomethyl group having at least one N-substituent selected from the class consisting of aliphatic groups, cycloaliphatic groups, aralkyl groups, and saturated divalent aliphatic groups which jointly with the nitrogen form a heterocyc e.

12. A water-resistant fllrn comprising a reac tion product of a cellulose ether'and an aldehyde having attached to the a-carbon atom an aminomethyl group having at least one N-substituent selected from the class consisting of aliphatic groups, cycioaliphatic groups, aralkyl groups, and saturated divalent aliphatic groups which Jointly with the nitrogen form a heterocycle.

13. Awater-resistant film comprising a reaction product oi! a water-soluble cellulose ether and a-dimethylaminomethyl isobutyraldehyde.

14. Textile material carrying a deposit of a .starch size which has been rendered insoluble 

